Clobazam Has Equivalent Efficacy to Carbamazepine and Phenytoin as Monotherapy for Childhood Epilepsy

PURPOSE: To compare the effectiveness of monotherapy clobazam (CLB) to carbamazepine (CBZ) and phenytoin (PHT) in children with epilepsy. METHODS: Children aged 2-16 years with newly diagnosed epilepsy or previous failure of one drug (for poor efficacy or side effects) were assigned to one of two study arms and then randomized--CLB versus CBZ or CLB versus PHT. Eligible children had partial epilepsies or only generalized tonic-clonic seizures. After a drug initiation protocol, monotherapy treatment mimicked the usual routines used by Canadian child neurologists. Blinding used a "double dummy" technique with blinded medication serum levels (6-point scale). Intention to treat analysis using survival curves assessed the primary endpoint--length of retention on the initial medication during the year after randomization. RESULTS: Fifteen centers entered 235 patients: 159 randomized to CLB versus CBZ and 76 to CLB versus PHT. Altogether, in all study arms, 119 received CLB, 78 CBZ, and 38 PHT. Overall, 56% continued to receive the original medication for 1 year with no difference between CLB and standard therapy (CBZ and PHT). Seizure control was equivalent for all three medications, as were side effects. PHT and CBZ induced more biologic side effects, such as rash, while CLB induced slightly more behavioral effects. Tolerance developed in 7.5% of patients receiving CLB, 4.2% with CBZ and 6.7% with PHT. CONCLUSIONS: CLB should be considered as "first line" monotherapy along with CBZ and PHT for all partial and selected generalized childhood epilepsies.